Studies in short-duration auditory fatigue: II. Recovery time.

Abstract

The effect upon recovery from auditory fatigue caused by short duration pure tones of several frequencies and intensities was detd. Four normal hearing subjects were used. Each was stimulated monaurally with an initial tone of 400 millisec, then, after a silent interval of variable duration, with a tone of 50 millisec. Tones of 500, 3000, and 8000 cps were used. Five detns. were taken at sensation levels of 10, 30, 50, and 70 decibels for the 1st or fatiguing tone using at each level silent intervals of 20, 40, 80, 120, 180, 240, or 300 millisec. Intensity of the 2d tone was varied randomly to obtain thresholds. Results indicate that fatigue increases with sensation level and frequency and is inversely related to the length of the inter-stimulus interval. Recovery from fatigue follows an exponential course with some stimulus intensities, departing from this course at other (weaker) intensities.